there's gold in them thar turds

Smith and her fellow researchers are also planning to test biosolids across the country for precious metals, to search for any geographic or demographic patterns in their distribution. So far, the group has collected waste from several small towns in the Rocky Mountains, rural areas, and big cities. Astonishingly, in nearly all the samples they’ve examined, the team has found commercially mineable concentrations of gold.

“What’s interesting is that we’re seeing nearly the same amount of gold in all of these samples,” Smith told me. “It seems like there’s some source of gold that’s prevalent across the board.”

It's not entirely clear how these precious metals are getting into our waste, Smith says. Potential culprits include hair products, cosmetics, and detergents. But humans could also be playing a more direct role, by concentrating the trace metals we eat during digestion, and sending gold-and-silver-fortified defecations down the tube.

Whatever the reason, one thing’s clear: our sewers are a lot prettier than we realized.